Children and a parents take a photo of a memorial with candles at Sparks Middle School
AP Photo

Sparks: The 12-year-old student who opened fire on a Nevada middle school campus, wounding two classmates and killing a teacher before he turned the gun on himself, got the weapon from his home, authorities has said.

School District police said they are still working to determine how the boy obtained the 9mm semi-automatic Ruger handgun used in the Monday morning spree at Sparks Middle School. The boy's parents are cooperating with authorities and could face charges in the case, police said.

Authorities say they are withholding the seventh-grader's name out of respect for his family.

At a news conference yesterday, law enforcement and school officials again lauded the actions of 45 year-old math teacher and former Marine Michael Landsberry, who tried to stop the rampage before he was killed.

The violence started before the first bell of the day rang, as students filed off buses and gathered for class. The boy opened fire outside a school building, hitting one 12-year-old student in the shoulder. He then headed toward a basketball court, where he encountered Landsberry.

The teacher walked calmly toward the shooter and lifted his hands, asking the boy to hand over his weapon.

"He was telling him to stop and put the gun down," student Jose Cazares told NBC's "Today" show Tuesday. "Then the kid, he yelled out 'No!' Like, he was yelling at him, and he shot him."

Landsberry suffered a fatal gunshot wound to the chest. Still, his actions gave students enough time to run to safety, according to County School District Police Chief Mike Mieras.

Police said they believe the shooter at one point tried to enter the school but couldn't open the door because of emergency lockdown procedures.

After killing Landsberry, the boy fired at a second student, hitting him in the abdomen. He then shot himself in the head.

The two 12-year-old boys who were wounded are in stable condition and recovering.